JP2007092148A - Hearth roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hearth roll having high durability which can keep the suitable temperature without making the unevenness of the surface temperature. <P>SOLUTION: A plurality of low heat-conductive round sheets 4 composed of an inorganic fiber sheet and a plurality of high conductive round sheets 5 composed of a metal sheet etc., are fitted in a laminated state on the outer periphery of a metal shaft 2 formed so as to pass through cooling water, and an outer tube 8 is fitted so as to cover the outer periphery of the low heat-conductive round sheets 4 and the high heat conductive round sheets 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hearth roll used for conveying a high-temperature rolled material.

  Patent Document 1 describes conventional examples of first to fourth hearth rolls shown in FIGS.

  The hearth roll of the first conventional example shown in FIG. 2A has a metal outer tube 15 formed of metal flanges 12 and 13 and a support ring 14 provided on the outer periphery of a hollow metal shaft 11 that is water-cooled inside. The outer tube 15 supports and conveys the rolled material. FIG. 2B shows the surface temperature distribution of the hearth roll of the first conventional example. As shown in the figure, the outer tube 15 is cooled only in the portions designated by the flanges 12 and 13 and the support ring 14, and the surface temperature varies greatly.

  The hearth roll of the second conventional example shown in FIG. 3 (A) is obtained by increasing the number of support rings 14 of the first conventional example, but as shown in FIG. 3 (B), the temperature of the outer tube 15 is increased. The variation cannot be made sufficiently small.

  The hearth roll of the third conventional example shown in FIG. 4A is obtained by filling the space between the metal shaft 11 and the outer tube 15 with a heat-resistant mortar 16 instead of the support ring 14. In this third conventional example, since the heat radiation from the central portion of the outer tube 15 is small, the temperature can be made substantially constant over a wide range of the outer tube 15 as shown in FIG. Since the heat cannot be radiated to the cooling water passing through the metal shaft 11 except for both end portions supported by the metal shaft 11, the central portion of the outer tube 15 becomes higher than the appropriate temperature, and is used in an oxidizing atmosphere. There is a problem that build-up occurs in which scale is generated and laminated on the surface of the hearth roll. Further, as shown in the lower side of FIG. 4A, there is a problem that the heat-resistant mortar 16 deteriorates due to use and the outer tube 15 cannot be supported and deformed.

  Further, in the hearth roll of the third conventional example, there is one in which a powder heat insulating material is packed in the space between the metal shaft 11 and the outer tube 15 in place of the heat-resistant mortar 16, but the central portion of the outer tube 15 is also used. The heat release from the pipe is small, and the temperature of the outer tube 15 becomes too high, causing buildup. Further, since it is difficult to completely fill the powder heat insulating material and to prevent leakage of the powder heat insulating material from the gap between the flange 13 and the outer tube 15, the inner side of the outer tube 15 is the same as in the third conventional example. A gap is generated in the outer tube 15, and deformation of the outer tube 15 cannot be prevented.

  In the fourth conventional example shown in FIG. 5A, a large number of discs 17 made of inorganic fiberboard are stacked and fitted in place of the heat-resistant mortar 16 of the third conventional example. The flange 13 fitted to the metal shaft 11 is fastened and fixed with a nut 18. In the fourth conventional example, the disc 17 is not deteriorated and the outer tube 15 cannot be supported even if it is repeatedly used. However, as shown in FIG. 5B, the disadvantage that the temperature of the central portion of the outer tube 15 becomes too high and build-up occurs in an oxidizing atmosphere has not been solved.

As shown in FIG. 6A, in the fifth conventional example in which the outer tube 15 of the fourth conventional example is omitted, the rolled material is supported not by metal but by a disk 17 of an inorganic fiber plate, so that it is transmitted from the rolled material. The amount of heat is small, and the surface temperature can be maintained at a substantially appropriate temperature as shown in FIG. However, as shown on the lower side of FIG. 6A, there is a problem that durability is insufficient because the disk 17 of the inorganic fiber board is worn when repeatedly used.
JP 11-29826 A

  As described above, in view of the problems of conventional hearth rolls, an object of the present invention is to provide a highly durable hearth roll that can be maintained at an appropriate temperature without varying the surface temperature.

  In order to solve the above-mentioned problems, the hearth roll according to the present invention is formed by laminating a plurality of low heat conduction disks and a plurality of high heat conduction disks on the outer periphery of a metal shaft formed to allow cooling water to pass. It is assumed that an outer tube is fitted so as to cover the outer periphery of the low heat conduction disk and the high heat conduction disk.

  According to this configuration, since the outer tube is supported by laminating the low heat conduction disk having excellent heat retention performance and the high heat conduction disk having excellent cooling capacity, the plurality of locations of the outer tube are supported while supporting the entire outer tube. The heat can be taken from and can be radiated to the cooling water passing through the metal shaft. Since the outer tube is cooled by being dispersed by a large number of high heat conducting disks, the surface temperature does not vary. Moreover, by laminating high heat conduction disks with high mechanical strength, the mechanical load on the low heat conduction disks can be reduced, and high durability can be obtained.

  In the hearth roll of the present invention, the low thermal conductive disk may be composed of an inorganic fiber board obtained by making inorganic fibers into a plate shape. Thereby, a low heat conductive disk becomes the thing excellent in heat resistance and durability, and heat conductivity is small, and can provide a highly durable hearth roll.

  Further, in the hearth roll of the present invention, the high thermal conductive disk can be composed of a metal plate excellent in heat resistance, durability, and workability.

  As described above, according to the present invention, the outer tube exposed to a high temperature is held by a large number of low heat conductive plates having excellent heat insulation properties and a large number of high heat conductive disks having excellent cooling properties. It can be dispersed and cooled by a high heat conduction disk. As a result, it is possible to provide a hearth roll that does not vary in the surface temperature of the outer tube and has high durability.

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1A shows a hearth roll 1 which is an embodiment of the present invention. The hearth roll 1 is made by making a hollow metal shaft 2 formed so that cooling water can be passed through the inside, a fixed flange 3 fitted on the metal shaft 2 and fixed by welding, and a binder added to the ceramic fiber. A number of low thermal conductive disks 4 fitted to the metal shaft 2 and a number of stainless steel plates dispersed and laminated between the low thermal conductive disks 4 fitted to the metal shaft 2. Along with the high heat conduction disk 5 and the fixed flange 3, the low heat conduction disk 4 and the movable flange 6 fitted so as to sandwich the high heat conduction disk 5 and the movable flange 6 are pressed against the fixed flange 3. By tightening, a double nut 7 that presses and fixes the low heat conduction disk 4 and the high heat conduction disk 5 and the outer periphery of the low heat conduction disk 4 and the high heat conduction disk 5 are fitted so as to cover one end. Welded to fixed flange 3 Consists outer tube 8 which consists of a constant has been SUS310S.

  In the present embodiment, the thicknesses of the low heat conduction disk 4 and the high heat conduction disk 5 are all the same. Since the four low heat conduction disks 4 and the one high heat conduction disk 5 are alternately arranged, and the four low heat conduction disks 4 are arranged at both ends, the low heat conduction disk 4 The total thickness is slightly larger than about 4 times the total thickness of the high thermal conductive disk 5.

  FIG. 1B shows the surface temperature distribution of the outer tube 8 when a high-temperature rolled material is conveyed by the hearth roll 1 having the above configuration. The outer tube 8 has a low temperature at both ends in contact with the fixed flange 2 or the movable flange 6, but the other portions are maintained at a temperature close to the appropriate temperature.

  The outer tube 8 receives heat substantially uniformly in the axial direction from the rolled material to be conveyed. The portion of the outer tube 8 that contacts the flanges 3, 6 or the high heat conduction disk 5 is the cooling water that is passed through the flange 3, 6 or the high heat conduction disk 5, and further through the metal shaft 2 to the metal shaft 2. However, since the low heat conduction disk 4 cannot take heat away from the outer tube 8, the portion of the outer tube 8 that contacts the low heat conduction disk is not cooled directly.

  For this reason, as shown in FIG. 1 (B), the surface temperature of the outer tube 8 is slightly higher at the portion in contact with the low heat conduction disk 4 and slightly lower at the portion in contact with the high heat conduction disk 5. However, since the high thermal conductive disk 5 is a thin plate, the amount of heat radiation per sheet is limited, and the surface temperature of the outer tube 8 is not greatly reduced locally. In addition, since one high heat conduction disk 5 is arranged for every four low heat conduction disks 4, the portion of the outer tube 8 that contacts the low heat conduction disk 4 is heated by heat conduction in the outer tube 8. The heat can be indirectly radiated through the conductive disk 5, and the temperature does not become too high. Thereby, since the surface temperature of the outer tube 8 is maintained appropriately, the scale does not build up.

  Since the hearth roll 1 supports the rolled material with the outer tube 8, there is no fear that the low heat conduction disk 4 is worn, and the low heat conduction disk 4 made of an inorganic fiber board is stable, so the hearth roll 1 is repeatedly used. Even if it does not deteriorate.

  Further, in the hearth roll 1 of the present invention, the total thickness of the low thermal conductive disk 4 is larger than the total thickness of the high thermal conductive disk 5, so that the cooling capacity of the outer tube 8 by the high thermal conductive disk 5 is low. The heat insulation ability by the disk 4 is superior. As a result, even when a rolled material of 1000 ° C. or higher is conveyed, the outer surface of the outer tube 8 is prevented from being overcooled while the metal shaft 2 is sufficiently cooled to increase the life of a bearing (not shown). The surface can be maintained at an appropriate temperature.

  A further feature of the hearth roll 1 of the present invention is that the ability to cool the outer tube 8 can be easily adjusted by changing the ratio of the low heat conduction disk 4 and the high heat conduction disk 5. For example, if the number of high heat conducting disks 5 is increased, the surface temperature of the outer tube 8 can be lowered without changing the cooling water and other conditions.

  The surface temperature of the outer tube 8 is high at the portion in contact with the low heat conduction disk 4 and is low at the portion in contact with the high heat conduction disk 5. However, the low heat conduction disk 4 and the high heat conduction disk 5 that are as thin as possible are used. By arranging the conductive disks 5 as dispersed as possible, the surface temperature can be made substantially uniform. For this reason, it is preferable to periodically laminate the low heat conduction disk 4 and the high heat conduction disk 5 in the central portion. Thereby, local overheating and overcooling of the outer tube 8 can be prevented, and prediction and adjustment of the surface temperature are facilitated.

  Further, in the hearth roll 1 of the present embodiment, the low heat conduction disk 4 and the high heat conduction disk 5 have the same thickness, but the low heat conduction disk 4 and the high heat conduction disk 5 having different thicknesses are laminated. Alternatively, the high thermal conductive disks 5 may be arranged in a distributed manner between the low thermal conductive disks 4.

  Further, in the hearth roll 1 of the present invention, the high heat conductive disk 5 is not limited to a stainless steel plate, and other high heat conductive materials such as other metals and graphite expanded sheets can be used.

  In the hearth roll 1 of the present invention, the outer tube 8 is not limited to a metal, and a ceramic crystal sleeve or the like can be used.

Sectional drawing and surface temperature distribution figure of the hearth roll of embodiment of this invention. Sectional drawing and surface temperature distribution figure of the 1st prior art example of a hearth roll. Sectional drawing and surface temperature distribution figure of the 2nd prior art example of a hearth roll. Sectional drawing and surface temperature distribution figure of the 3rd prior art example of a hearth roll. Sectional drawing and surface temperature distribution figure of the 4th prior art example of a hearth roll. Sectional drawing and surface temperature distribution figure of the 5th prior art example of a hearth roll.

Explanation of symbols

1 Hearth Roll 2 Metal Shaft 3 Fixed Flange 4 Low Heat Conduction Disk 5 High Heat Conduction Disk 6 Movable Flange 7 Double Nut 8 Outer Tube

Claims (3)

  A plurality of low heat conduction disks and a plurality of high heat conduction disks are stacked and fitted on the outer periphery of a metal shaft formed to allow cooling water to pass through, and the low heat conduction disks and the high heat conduction disks A hearth roll comprising an outer tube fitted to cover the outer periphery.   The hearth roll according to claim 1, wherein the low thermal conductive disk is made of an inorganic fiber board.   The hearth roll according to claim 1 or 2, wherein the high thermal conductive disk is made of a metal plate.

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